Study of fundamental limits of solid-state nuclear spin gyroscopy based on NV centers in diamond

• Applicant: Professor Dr. Jörg Wrachtrup
• Subject Area: Experimental Condensed Matter Physics ; Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas
• Term: since 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 445397527

The precise detection of gyration is a challenging problem in basic science and of significant relevance for applications. A variety of methods based on classical angular momentum conservation, quantum standards as well as the Sagnac effect have been developed. Recently the demand for precision and compact (!) inertial navigation is increasing, caused by the surge of activities on autonomous technical systems. Among other technologies the observation of a nuclear spin ensemble precession is a promising method to measure rotation precisely. State of the art methods are based on phase-locked precession of ensembles of hyperpolarized nuclear spins in hot atomic alkali metal vapours, which however is hard to integrate. Here, we aim to realize such a method in a solid with the prospect to develop compact precision gyroscopes. Our approach is based on nitrogen-vacancy (NV) centers in diamond, shown to have unparalleled optical and spin properties under ambient conditions. We will utilize an ensemble of nuclear spins as reference for gyration which allows miniaturizing the sensing element and make it compatible with chip technology. Taking into account well-studied parameters of nuclear spins in the diamond material, the estimated theoretical limit of rotation sensor is on the order of millidegree per hour which puts this technology on par with fiber-based ring-laser optical gyroscopes with the advantage of a significantly smaller size. In comparison to the micro electromechanical (MEMS) technology, the nuclear spin gyroscope will show significantly better bias stability characteristics. In the course of the project, the diamond material will be optimized towards the usage of nuclear spin ensembles. The project will include research on developing novel control protocols for rotational sensing, and its fundamental precision limits. The latter part of the project is devoted to studies of minimizing and compensating the drifts and systematic effects in a possible optimal sensing protocol through utilizing novel control methods and quantum control techniques such as error correction and coherent feedback. The project will be pursued in a collaboration of two laboratories: Prof. Wrachtrup from the German side and Prof. Akimov from Russian side. The German side has a broad and longstanding track record in developing sensing protocols and advancing diamond materials, while the Russian side already has ongoing research work on proof of principles gyroscopic measurements with NV in diamond. By joining forces, this collaboration has the potential to enable rotational sensing with NV centers by exploring novel diamond materials and sensing protocols.

• DFG Programme: Research Grants
• International Connection: Russia
• Partner Organisation: Russian Science Foundation, until 3/2022
• Cooperation Partner: Professor Alexey Akimov, Ph.D.